Balanced piston



(NoModeL) J. P. BENOIT,

BALANCED PISTON. E No. 352,298. Patented Nov. 9, 1886.

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UNITED STATES- PATENT OFFICE.

JOHN P. BENOIT, OF DETROIT, MICHIGAN.

- BALANCED PISTON.

SPECIFICATION forming part of Letters Patent No. 352,293, dated November 9, 1886.

Application tiled July 29, 1886. Serial No. 209,395. (No model.)

To all whom it may concern:

Be it known that I, JOHN I. BENOIT, of Detroit, in the county of Wayne and State of Michigan, having invented new and useful Improvements in Balanced Pistons; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to certain new and usefulimprovements in pistons which reciprocate in horizontal cylinders; and the invention consists in the means employed for balancing the weight of the piston so that it .will equally bear on all sides, instead of bringing its weight to bear exclusively on the lower halt of the cylinder, as is the casein all constructions of pistons in present use.

In the drawings, Figure l is a'vertical central longitudinal scctiorrof my improved balanced piston. Fig. 2 is a cross-section thereof. Fig. 3 is a detached perspective view of one of the halves of a packing-ring.

A is the cylinder, B the piston-rod, and O the piston, all of known construction, with the exception of the packing, which embodies my invention. This packing consists, essentially, of the packing-rings E, each ring made in halves, so placed around the piston that the joints a between the ends of the halves of each expansion thereof.

packing-ring are in vertical line, or nearly so, with the center of the piston. Each half of the packing-rings E is connected with the piston in such manner that the steamis thereby cut off from the portion above such connection, without interfering, however, with the radial This connection is made at or near the center of each half of the packing-rings, preferably above the horizontal center line of the piston, and to this end studs 12 of the Width of the packing-ring aresecured to the halves of each ring and engaged into corresponding recesses, 0, provided therefor in the body of the piston. By these means the ring is detachable, and thestuds cut off the steam-communication behind the upper and lower portion of the packing-ring, and around each of the packing-rings E is placed a packing-ring, F, of the ordinary descriptionthat is, one that acts by its own elasticity.

Steam-passages cl are provided in the body of the piston, which lead from the steamspaces of the cylinder to the back of each packing-ring, but only to the lower portion thereof,

as shown, theupper portion thereof being unprovided therew1th.

Suppose a piston of this construction to be used in a steam-engine, it will be seen that the steanrwill enter through the passages before described, back of the lower part of the piston-rings E, while it is cut off, or nearly so, from the upper part by the studs 1), and it must therefore exercise a lifting action on the piston. This lifting actioncan be ascertained for a specific case and the parts so proportioned that it will balance, or nearly so, the weight of the piston when in operation.

By practical experiments I have demonstrated the successful operation of the device, which has resulted in a large saving of power and a greatly-diminished wear of the piston and cylinder.

What I claim as my invention is 1. in a balanced horizontal piston, a pistonpacking consisting of an inner and outer ring, the inner ring being vertically divided and laterally connected'with the piston, and of steam-passages leading back of the lower portion of the inner ring, substantially as described. I

2. In a balanced horizontal piston, a piston packingconsisting of an inner and outer ring, the inner ring being vertically divided in halves, each half being laterally connected 'with the piston at a point above a horizontal line through t..e center of the piston, and of steam passages in the piston terminating back of the lower portion of theinner ring, sub stantially as described.

8. Ina balanced horizontal piston, a pistonpacking consisting of an inner and outer ring, the inner ring being vertically divided in halves, each half having a laterally-sliding connection with the piston in a horizontal line passing above the center of the piston, and of steanrpassages in the piston leading back of the lower portion of the inner ring, substantiall y as described.

4. In a balanced horizontal piston, the combination, with the piston, of the two sets of inner and outer rings, E F, the former being vertically divided in halves, and having studs 12 engaging into holes 0 of the piston, an of the steam-passages d in the piston, all arra ged and operating substantially as described.

Witnesses: JOHN P. BENOI H. S. SPRAGUE, E. SoULLY. 

